Midas 7 was the first completely successful flight in the series, coming in between the two launch failures. Ten missile tests were detected by 7 in its month-long operation. Also the date on that video is incorrect, it should be 5/9/63, not 73.

I noticed SDASM just uploaded footage of Atlas 45F the other day. This one has long been a staple of rocket fail highlight reels, but the high speed film is new. No aftermath photos unfortunately.

Anyway, 45F was launched from OSTF-2 at Vandenberg on the evening of 10/4/63. The B-1 engine failed to start and the resultant asymmetrical thrust caused the missile to tip over and rotate away from the silo cap, impacting the ground with the almost full propellant load lighting up the night sky in a spectacular fireball. The silo was largely spared significant damage and it was restored to use in two months, hosting Missile 109F's launch on 12/18/63, the finale Atlas R&D flight.

On 4/3/64, almost exactly six months after 45F's errant flight, Missile 3F launched from OSTF-2 and repeated the same failure. The B-1 engine did not start and the Atlas fell to the ground, exploding. This time, it would be six months before OSTF-2 was used again. Investigation of the two flight failures found that the B-1 main fuel valve was clogged with hypergol residue from repeated test firings and stuck shut. On 3F, the valve actually did open, but after activation of the engine igniter so mainstage engine operation was never achieved.

Remedies for this failure mode included conducting improved purges of the missile fuel system to clear out hypergol residue and a recall of all main fuel valves on operational Atlas missiles, in particular ones that had been in service for an extended period of time, and replacement of the fuel valve acutators.

Stuck engine valves were not a problem unique to Atlas, on 5/1/63, some five months before 45F, a nighttime Titan I operational test at VAFB also ended in the missile toppling and exploding when the LR-87 engines failed to start properly.